I think that the most common way to value Bitcoin is like valuing other currency by another currency.
Seeing to it that we all know all the factors that causes or affects supply and demand equilibrium.
Also the time we hold bitcoins. Time is very important factor.
Of course yes i valuing bitcoin because i earn and have extra income so who cant value bitcoin if they are earning a profit or xtra income. When i first time to hear bitcoin i didnt belive because i thnk this is like others scam, pyeamiding or networking so i didnt believed biin bitcoin but right now i believe that you can earn using bitcoin.